Difference between revisions of "Minutes 5-2-2007"
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− | ==Cathode Prototyping== | + | ==#Cathode Prototyping== |
- Brian has been in contact with the manufacturer of our dummy cathode | - Brian has been in contact with the manufacturer of our dummy cathode | ||
boards about the few Ohm strip-to-strip resistance. They believe that | boards about the few Ohm strip-to-strip resistance. They believe that | ||
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the solid Rohacell piece. | the solid Rohacell piece. | ||
− | ==Circuit Boards== | + | ==#Circuit Boards== |
- We are still awaiting the results from Monte Carlo on the expected | - We are still awaiting the results from Monte Carlo on the expected | ||
chamber rates with the new reduced material design. This will allow | chamber rates with the new reduced material design. This will allow | ||
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testing in August. | testing in August. | ||
− | ==New Prototype Cathodes== | + | ==#New Prototype Cathodes== |
- There was a hiccup in the order for the +/-75 deg cathodes for the | - There was a hiccup in the order for the +/-75 deg cathodes for the | ||
small-scale prototype. CCT marketing did not have the 2-micron thick | small-scale prototype. CCT marketing did not have the 2-micron thick | ||
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expect the first boards to arrive in July. | expect the first boards to arrive in July. | ||
− | ==FDC CD-2 Document== | + | ==#FDC CD-2 Document== |
- Still waiting for input from Monte Carlo. Richard Jones is working | - Still waiting for input from Monte Carlo. Richard Jones is working | ||
on the studies of the photon conversions in the inactive materials. | on the studies of the photon conversions in the inactive materials. | ||
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We expect these studies to be completed in about a week. | We expect these studies to be completed in about a week. | ||
− | ==Magnetic Field Tests== | + | ==#Magnetic Field Tests== |
- Plans continue to be fleshed out. DSC and Simon have prepared a | - Plans continue to be fleshed out. DSC and Simon have prepared a | ||
test plan document and it is ready to be turned into Volker. We | test plan document and it is ready to be turned into Volker. We | ||
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the field on the cathode resolution. | the field on the cathode resolution. | ||
− | ==Work List== | + | ==#Work List== |
- The FDC short-term work list has been posted on the FDC web site | - The FDC short-term work list has been posted on the FDC web site | ||
(see http://www.jlab.org/Hall-D/detector/fdc/). DSC is still | (see http://www.jlab.org/Hall-D/detector/fdc/). DSC is still |
Revision as of 17:31, 7 May 2007
FDC Weekly Meeting
Date: May 2, 2007
Participants: Daniel, Simon, Kim, Roger, Chuck, Fernando, Brian
Next Meeting: Wednesday, May 9, 2007 @ 1:30 p.m.
Contents
#Cathode Prototyping
- Brian has been in contact with the manufacturer of our dummy cathode boards about the few Ohm strip-to-strip resistance. They believe that they did not etch for long enough. They will probably ask us to send them back a sample of the problematic "boards" for checking. - Brian indicated that Brown and Sharp has indicated that they can perform the measurements of our no-backing cathode planes to measure the strip-to-strip separations (to look for distortions) as well as to measure the surface flatness. Brian did not specify to them that we would prefer that these measurements are done with the cathodes sitting vertically (to eliminate gravitational sag). He will follow up with the company. If they cannot do the measurements in this position, we could fabricate a Rohacell disk to sit under the cathode surface. - Brian will be away for most of May on travel. DSC indicated that upon his return we need to work to consider the designs for the cathode backing to reduce the density of this support material with respect to the solid Rohacell piece.
#Circuit Boards
- We are still awaiting the results from Monte Carlo on the expected chamber rates with the new reduced material design. This will allow us to specify the HV segmentation to enable Kim to complete the design for the HVTB boards. - We are planning on a design employing only 2 STBs and 2 HVTBs per wire frame. Roger and Kim are awaiting word on where to put the daughter board connectors (and the connector type) so that they can complete the design of the STBs. - Roger found a 4-kV rated capacitor that is the same height as the 3-kV caps that he had found before. They are a bit wider, but this should not be an issue. - DSC asked Fernando to look into manufacturing a circuit board for the small-scale prototype from HVPF. We would like to compare its properties to the standard FR-4 boards. - DSC asked Fernando to begin to consider a design of the preamp daughter board that will be compatible for use with the small-scale prototype. We expect the first run of ASICs to be available for our testing in August.
#New Prototype Cathodes
- There was a hiccup in the order for the +/-75 deg cathodes for the small-scale prototype. CCT marketing did not have the 2-micron thick copper material. Brian and Roger will work out how to get the 5-micron thick copper (on 1-mil kapton) completed while someone tries to get the 2-micron thick copper board material to CCT. We should expect the first boards to arrive in July.
#FDC CD-2 Document
- Still waiting for input from Monte Carlo. Richard Jones is working on the studies of the photon conversions in the inactive materials. Simon will follow up with him to find out the status of this work. We need to know if our composite cathode frames are "good enough" or if we need to work harder to reduce the material thickness. There is not much more that we can do except to replace the CH2 with carbon-fiber composites, but this is minimal. Matt Shepard is working on the rate studies with the reduced material in the active portion of the chamber. We expect these studies to be completed in about a week.
#Magnetic Field Tests
- Plans continue to be fleshed out. DSC and Simon have prepared a test plan document and it is ready to be turned into Volker. We are working on several fronts to be able to identify some detectors to be used external to the field to define a track through the FDC. We would like sufficient precision on this track measurement to determine the centroid shift along the wire. Even without these external measurements, we should be able to quantify the effect of the field on the cathode resolution.
#Work List
- The FDC short-term work list has been posted on the FDC web site (see http://www.jlab.org/Hall-D/detector/fdc/). DSC is still waiting for feedback and comments from the group.
Minutes prepared by Daniel. Send any comments or corrections along.